PPP-B2b satellite clock error correction value abnormal jump processing method and system

Abstract

The invention relates to a PPP-B2b satellite clock correction value abnormal jump processing method and system, and the method comprises the steps: carrying out the calculation of a reference variation when a GPS reference satellite of a current epoch and a GPS reference satellite of a previous epoch are switched, and correcting a clock correction value; superposing the clock error correction values of the GPS satellite and the BDS-3 satellite to a broadcast ephemeris, and recovering to obtain a precise satellite clock error; calculating a precision satellite clock difference value of each satellite; when the precision satellite clock difference value of the target satellite is greater than a preset threshold value, determining that abnormal jump exists; if the target satellite is not the reference satellite, initializing clock error exception processing parameters in a positioning observation equation of the target satellite; if the satellite is the reference satellite, initializing clock error exception processing parameters in the positioning observation equations of all satellites of the current epoch; therefore, the abnormal jump part of the clock correction value is absorbed. The real-time PPP positioning result jump caused by the clock error abnormal value is avoided, and the continuity and reliability of the PPP-B2b precision positioning result are improved.

Description

Technical Field

[0001] The present invention relates to the field of satellite navigation and positioning technology, and in particular to a method and system for processing abnormal jumps of PPP-B2b satellite clock correction values. Background Art

[0002] The correction products broadcast by China's BeiDou-3 Navigation Satellite System (BDS-3) include precise satellite orbits, precise clock errors, and inter-symbol biases. Compared to traditional real-time PPP (PPP) technologies that rely on the internet to obtain correction data, PPP-B2b achieves real-time kinematic positioning by simply receiving PPP-B2b corrections broadcast by GEO satellites. This system meets the BDS-3 / GPS dual-system real-time PPP convergence time of less than 20 minutes, achieving centimeter-level horizontal positioning accuracy under static observation conditions and decimeter-level (10-20 cm) real-time positioning performance under dynamic scenarios. The emergence of BDS-3 PPP-B2b establishes a new satellite-based augmented real-time precise point positioning model. By broadcasting corrections from satellites, BDS-3 eliminates dependence on terrestrial communication networks and equipment, forming a precise positioning augmentation system that works heterogeneously with ground-based augmentation systems. This system effectively complements ground-based augmentation real-time precise positioning and provides a viable alternative for implementing real-time PPP.

[0003] However, in real-time precise point positioning using PPP-B2b GPS or BDS-3 systems, the satellite clock corrections broadcast by GEO satellites exhibit random, irregular jumps. This directly results in out-of-limit deviations (typically exceeding 3 ns) in individual satellite clock corrections. These anomalies arise from factors such as frequency drift of the onboard atomic clock, satellite-to-ground time synchronization errors, and transient interference in the correction broadcast link. These factors can disrupt the continuity of the PPP-B2b satellite clock corrections, leading to sudden offsets (maximum horizontal offset exceeding 1 meter) and filter reconvergence in real-time positioning results. Therefore, a real-time detection and processing method for these random, irregular jumps in PPP-B2b satellite clock corrections is urgently needed to ensure the continuous and stable computation of PPP-B2b real-time PPP solutions and avoid sudden positioning errors or even reconvergence caused by clock correction anomalies. Summary of the Invention

[0004] In order to solve the above technical problems, the technical solution adopted by the present invention is: In a first aspect, a method for processing abnormal jumps in PPP-B2b satellite clock correction values ​​is provided, comprising: Collect clock correction values ​​and broadcast ephemeris of PPP-B2b GPS satellites and BDS-3 satellites through user receivers; determine whether the GPS reference satellite is switched between the current epoch and the previous epoch according to the clock correction value of the GPS satellite; If the GPS reference satellite is switched between the current epoch and the previous epoch, the reference change amount is calculated according to the clock correction value of the common view GPS satellite between the current epoch and the previous epoch, the clock correction value of all visible GPS satellites in the current epoch is corrected according to the reference change amount, and the corrected clock correction value of the GPS satellite is obtained; The corrected clock correction value of the GPS satellite and the clock correction value of the BDS-3 satellite are superimposed to the broadcast ephemeris, the satellite clock difference parameter is calculated, and the precise satellite clock difference is recovered according to the satellite clock difference parameter; The precise satellite clock differences between the current epoch and the previous epoch are differentially processed to obtain the precise satellite clock difference value of each satellite; when the precise satellite clock difference value of the target satellite is greater than a preset threshold, it is determined that the clock correction value of the target satellite in the current epoch has an abnormal jump; determine whether the target satellite is a reference satellite; If not, the clock abnormality processing parameter in the positioning observation equation of the target satellite is initialized, so as to absorb the abnormal jump part of the clock correction value; If yes, the clock abnormality processing parameter in the positioning observation equation of all satellites in the current epoch is initialized, so as to absorb the abnormal jump part of the clock correction value.

[0005] Further, the type of broadcast ephemeris is divided into GPS LNAV broadcast ephemeris and BDS-3 CNAV1 broadcast ephemeris.

[0006] Further, determining whether the GPS reference satellite is switched between the current epoch and the previous epoch comprises: obtaining the clock correction value of the GPS satellite in the previous epoch; comparing the clock correction value of the GPS satellite in the previous epoch with the clock correction value of the GPS satellite in the current epoch; If the clock correction value of the target GPS satellite in the current epoch is 0, the target GPS satellite is taken as the GPS reference satellite, and it is determined whether the GPS reference satellite in the current epoch is consistent with the GPS reference satellite in the previous epoch; if not, it is determined that the GPS reference satellite is switched; if yes, it is determined that the GPS reference satellite is not switched; If the clock correction value of all GPS satellites in the current epoch is not 0, the GPS reference satellite cannot be determined, and it is determined that the GPS reference satellite is not switched; If the clock correction value of multiple GPS satellites in the current epoch is 0, the GPS reference satellite in the previous epoch is taken as the GPS reference satellite in the current epoch, and it is determined that the GPS reference satellite is not switched.

[0007] Furthermore, a reference variation is calculated based on the clock correction values ​​of the common-view GPS satellites in the current epoch and the previous epoch, and the clock correction values ​​of all visible GPS satellites in the current epoch are corrected based on the reference variation to obtain a corrected clock correction value of the GPS satellite, including: Perform differential processing on the clock correction values ​​of the common-view GPS satellites of the current epoch and the previous epoch to obtain the differential value of each common-view GPS satellite; Calculate the average of the differential values ​​of all common-view GPS satellites to obtain the baseline change between the current epoch and the previous epoch; The reference variation is used to correct the clock error correction values ​​of all visible GPS satellites in the current epoch to obtain the corrected clock error correction value of the GPS satellite.

[0008] Furthermore, the GPS satellite clock correction value and the BDS-3 satellite clock correction value are superimposed on the broadcast ephemeris, and the satellite clock error parameters are calculated. The precise satellite clock error is recovered based on the satellite clock error parameters, including: The satellite clock error parameters are calculated by adding the GPS satellite clock error correction value and the BDS-3 satellite clock error correction value to the broadcast ephemeris. ; According to the satellite clock error parameters Recover precise satellite clock error , the calculation formula is: ; in, represents the speed of light under vacuum conditions; Indicates the preset clock correction value, which is preset according to the PPP-B2b correction product.

[0009] Furthermore, the GPS satellite clock correction value and the BDS-3 satellite clock correction value are superimposed on the broadcast ephemeris to calculate the satellite clock error parameters. After the precise satellite clock error is recovered based on the satellite clock error parameters, the following steps are also included: A clock error processing parameter is added to the positioning observation equations of the pseudorange and carrier phase of each satellite at each frequency of PPP-B2b. In the first epoch, the satellite with the highest elevation angle is selected as the reference satellite for subsequent epochs. The value of the positioning observation equation of the reference satellite is set to 0 to eliminate the rank deficiency of the positioning observation equation. The GPS / BDS-3 dual-system dual-frequency non-combined real-time PPP positioning model of PPP-B2b is expressed as: ; ; Wherein, C represents BDS-3; G represents GPS; s represents satellite identifier; r represents user receiver; j represents satellite signal frequency; and represent the pseudorange observations of BDS-3 satellites and GPS satellites minus the calculated values, respectively; and denote the carrier phase observations of BDS-3 satellites and GPS satellites minus the calculated values, respectively; and represent the station-satellite line-of-sight unit vectors of the BDS-3 satellite and the GPS satellite respectively; represents the three-dimensional position of the user receiver r; represents the product of the speed of light and the receiver clock error estimated by the BDS-3 satellite, represents the product of the speed of light and the receiver clock error estimated by the GPS satellite, and It absorbs the pseudo-range hardware delay of BDS-3 satellites and GPS satellites at the user receiver end respectively; and represent the tropospheric projection coefficients of BDS-3 satellite and GPS satellite respectively; It represents the wet delay in the tropospheric zenith direction at the user receiver end; and represent the ionospheric conversion coefficients of BDS-3 satellite and GPS satellite respectively; and denote the ionospheric delay estimates on the slant paths of the first frequency for the BDS-3 satellite and the GPS satellite, respectively. It only absorbs the pseudo-range hardware delay at the user receiver end. It absorbs the pseudorange hardware delay of the user receiver and the uncorrected pseudorange hardware delay of the GPS satellite. and represent BDS-3 satellites and GPS satellites respectively. and The jth frequency of the BDS-3 satellite and the GPS satellite absorbs the pseudorange hardware delay and phase hardware delay of the satellite end, and absorbs the ambiguity estimation of the pseudorange hardware delay and phase hardware delay of the user receiver end; and They represent the clock difference abnormal processing parameters added to the positioning observation equations of BDS-3 satellites and GPS satellites respectively.

[0010] Furthermore, the satellite clock error of PPP-B2b shows relatively stable characteristics within each continuous arc, and the clock error abnormality processing parameters are set to a random walk process.

[0011] In a second aspect, a PPP-B2b satellite clock correction value abnormal jump processing system is provided, comprising: Data acquisition module, used to collect clock correction values ​​and broadcast ephemeris of PPP-B2b GPS satellites and BDS-3 satellites through user receivers; The GPS reference satellite switching determination module is used to determine whether the GPS reference satellite of the current epoch and the previous epoch has switched based on the clock error correction value of the GPS satellite; A GPS satellite clock error correction module is used to calculate a reference change based on the clock error correction values ​​of the common-view GPS satellites of the current epoch and the previous epoch if the GPS reference satellites of the current epoch and the previous epoch are switched, and to correct the clock error correction values ​​of all visible GPS satellites of the current epoch based on the reference error correction value to obtain a corrected clock error correction value of the GPS satellite; The satellite clock error recovery module is used to superimpose the corrected clock error values ​​of the GPS satellite and the clock error correction values ​​of the BDS-3 satellite on the broadcast ephemeris, calculate the satellite clock error parameters, and recover the precise satellite clock error based on the satellite clock error parameters; The abnormal jump detection module is used to perform differential processing on the precise satellite clock error of the current epoch and the previous epoch to obtain the precise satellite clock error difference value of each satellite; when the precise satellite clock error difference value of the target satellite is greater than a preset threshold, it is determined that there is an abnormal jump in the clock error correction value of the target satellite in the current epoch; The abnormal jump processing module is used to determine whether the target satellite is a reference satellite; if not, the clock error abnormal processing parameters in the positioning observation equation of the target satellite are initialized to absorb the abnormal jump part of the clock error correction value; if so, the clock error abnormal processing parameters in the positioning observation equations of all satellites in the current epoch are initialized to absorb the abnormal jump part of the clock error correction value.

[0012] The beneficial effects achieved by the present invention are: The clock correction values ​​and broadcast ephemeris of the GPS satellites and BDS-3 satellites of PPP-B2b are collected by the user receiver; the clock correction values ​​of the GPS satellites are used to determine whether the GPS reference satellites of the current epoch and the previous epoch have switched; if the GPS reference satellites of the current epoch and the previous epoch have switched, the reference change is calculated based on the clock correction values ​​of the common-view GPS satellites of the current epoch and the previous epoch, and the clock correction values ​​of all visible GPS satellites of the current epoch are corrected based on the reference change to obtain the corrected clock correction value of the GPS satellite; the corrected clock correction value of the GPS satellite and the clock correction value of the BDS-3 satellite are superimposed on the broadcast ephemeris to calculate The precise satellite clock error parameters are recovered based on the satellite clock error parameters. The precise satellite clock error between the current epoch and the previous epoch is differentially processed to obtain the precise satellite clock error differential value for each satellite. When the precise satellite clock error differential value of the target satellite is greater than a preset threshold, it is determined that there is an abnormal jump in the clock error correction value of the target satellite in the current epoch. The system then determines whether the target satellite is a reference satellite. If not, the clock error abnormality processing parameters in the positioning observation equation of the target satellite are initialized to absorb the abnormal jump in the clock error correction value. If so, the clock error abnormality processing parameters in the positioning observation equation of all satellites in the current epoch are initialized to absorb the abnormal jump in the clock error correction value. To address the random abnormal jump in satellite clock error correction values ​​in PPP-B2b, the system recovers the PPP-B2b precise clock error and introduces the clock error abnormality processing parameters in the positioning equation to detect and process random abnormal clock error jumps in real time. This can avoid jumps in real-time PPP positioning results caused by clock error abnormality and improve the continuity and reliability of PPP-B2b real-time precise positioning results. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 This is a flow chart of a method for processing abnormal jumps in PPP-B2b satellite clock correction values ​​according to the present invention; Figure 2 This is a structural diagram of the PPP-B2b satellite clock correction value abnormal jump processing system of the present invention. DETAILED DESCRIPTION

[0014] The present invention will be further described below in conjunction with the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solutions of the present invention and are not intended to limit the scope of protection of the present invention.

[0015] like Figure 1 As shown, an embodiment of the present invention provides a method for processing abnormal jumps of PPP-B2b satellite clock correction values, including: 101, collect clock correction values ​​and broadcast ephemeris of PPP-B2b GPS satellites and BDS-3 satellites through user receivers; The user receiver simultaneously collects GPS L1 / L2 and BDS-3 B1I / B3I observation data and decodes two types of navigation messages, LNAV (GPS navigation message) and CNAV1 (BDS-3 navigation message), in real time. It also receives high-precision satellite clock corrections, satellite orbit corrections, DCB corrections, and antenna phase center deviation (PCO / PCV) auxiliary augmentation data, broadcast by BeiDou-3 geostationary orbit (GEO) satellites via the PPP-B2b augmentation signal. Broadcast ephemeris includes GPS LNAV broadcast ephemeris and BDS-3 CNAV1 broadcast ephemeris.

[0016] 102, determining whether a switch occurs between the GPS reference satellites of the current epoch and the previous epoch based on the GPS satellite clock error correction value; Considering the frequent switching of PPP-B2b GPS satellite clock error references, the clock error correction values ​​of the GPS satellites in the previous epoch are dynamically stored and compared with the clock error correction values ​​of the GPS satellites in the current epoch. The satellite with zero clock error correction is selected as the GPS reference satellite. If the clock correction value of only one target GPS satellite in the current epoch is 0, the target GPS satellite is used as the GPS reference satellite, and it is determined whether the GPS reference satellite in the current epoch is consistent with the GPS reference satellite in the previous epoch; if they are inconsistent, it is determined that a GPS reference satellite switch has occurred, and the subsequent step 103 is executed; if they are consistent, it is determined that a GPS reference satellite switch has not occurred; If the clock correction values ​​of all GPS satellites in the current epoch are not zero, the clock correction values ​​of the epoch are considered to be incorrect, and the GPS reference satellite of the current epoch cannot be determined. It is determined that no GPS reference satellite switch has occurred, and the clock correction values ​​of all satellites are not included in the subsequent reference unification process; If the clock error correction values ​​of multiple GPS satellites in the current epoch are 0, the GPS reference satellite of the previous epoch is used as the GPS reference satellite of the current epoch, and it is determined that no GPS reference satellite switching has occurred, thereby achieving reference consistency processing of multi-period observation data.

[0017] 103, calculating a reference change based on the clock correction values ​​of the common-view GPS satellites in the current epoch and the previous epoch, and correcting the clock correction values ​​of all visible GPS satellites in the current epoch based on the reference change to obtain a corrected clock correction value of the GPS satellite; When the GPS reference satellites between adjacent epochs are switched, a reference consistency correction model needs to be constructed based on the clock correction values ​​of the common-view GPS satellites. Specifically: Perform differential processing on the clock correction values ​​of the common-view GPS satellites of the current epoch and the previous epoch to obtain the differential value of each common-view GPS satellite; Calculate the average of the differential values ​​of all common-view GPS satellites to obtain the baseline change between the current epoch and the previous epoch; The reference variation is used to correct the clock error correction values ​​of all visible GPS satellites in the current epoch to obtain the corrected clock error correction value of the GPS satellite. To ensure the continuity of reference transfer, in the scenario of multiple reference satellite switching, it is necessary to update the overall reference correction based on the historical accumulated reference offset and the differential mean of the current epoch, thereby weakening the clock reference jump error caused by frequent changes of reference satellites and obtaining a stable sequence of GPS satellite corrected clock correction values.

[0018] 104. Superimpose the corrected clock error values ​​of the GPS satellite and the clock error correction values ​​of the BDS-3 satellite on the broadcast ephemeris, calculate the satellite clock error parameters, and recover the precise satellite clock error based on the satellite clock error parameters. The satellite clock error parameters are calculated by adding the GPS satellite clock error correction value and the BDS-3 satellite clock error correction value to the broadcast ephemeris. ; According to the satellite clock error parameters Recover precise satellite clock error , the calculation formula is: ; in, represents the speed of light under vacuum conditions; Indicates the preset clock correction value, which is preset according to the PPP-B2b correction product.

[0019] 105. Perform differential processing on the precise satellite clock errors of the current epoch and the previous epoch to obtain precise satellite clock error differential values ​​of each satellite. When the precise satellite clock error differential value of the target satellite is greater than a preset threshold, it is determined that an abnormal jump occurs in the clock error correction value of the target satellite in the current epoch. A threshold is set based on prior experience. If the precise satellite clock error difference value of a satellite's clock error correction value exceeds the preset threshold, it is considered that the satellite clock error value of the current epoch has an abnormal jump.

[0020] 106, determining whether the target satellite is a reference satellite; When the target satellite is not a reference satellite, execute step 107; when the target satellite is a reference satellite, execute step 108.

[0021] 107, initialize the clock error abnormality processing parameters in the positioning observation equation of the target satellite, thereby absorbing the abnormal jump part of the clock error correction value; The target satellite is not the reference satellite, the clock error anomaly processing parameter in the positioning observation equation of the target satellite is initialized, the satellite clock error of the PPP-B2b presents a relatively stable feature in each continuous arc, and the clock error anomaly processing parameter is set as a random walk process.

[0022] 108, the clock error anomaly processing parameter in the positioning observation equation of all satellites of the current epoch is initialized, so as to absorb the abnormal jump part of the clock error correction value.

[0023] The target satellite is the reference satellite, the clock error anomaly processing parameter in the positioning observation equation of all satellites of the current epoch is initialized, the clock error anomaly processing parameter estimated based on the latest observation information can effectively absorb the abnormal jump part of the clock error correction value of the PPP-B2b satellite, and the robustness between the positioning filtering estimation parameters and the continuity of the positioning are ensured.

[0024] In steps 107 and 108 of the embodiment shown above, Figure 1 The positioning observation equation and the clock error anomaly processing parameter of the satellite are pre-existing in steps 107 and 108 of the embodiment shown above, there is an initial systematic deviation in the existing PPP-B2b GPS and BDS-3 system satellite, the initial systematic deviation will be absorbed by the phase ambiguity parameter in the parameterization process, and the pseudorange observation will directly reduce the precision of the pseudorange in the positioning convergence stage, so as to not affect the positioning precision after convergence, but will reduce the precision of the pseudorange observation value and affect the early convergence time of the positioning; therefore, in order to compensate for this part of the deviation, the PPP-B2b real-time positioning model will introduce an initial satellite clock deviation compensation parameter in the positioning observation equation of the pseudorange of each satellite, but the random abnormal value of the satellite clock error is a non-normal phenomenon, which will not only affect the pseudorange, but also affect the carrier phase observation, therefore, an abnormal clock error processing parameter is added in the positioning observation equation of the pseudorange and the carrier phase of each satellite and each frequency of the PPP-B2b to absorb the influence of the clock error abnormal value; Preferably, in some embodiments of the application, step 104, the corrected clock error correction value of the GPS satellite and the clock error correction value of the BDS-3 satellite are superimposed to the broadcast ephemeris, the satellite clock error parameter is calculated, and after the precise satellite clock error is recovered according to the satellite clock error parameter, it further includes: A clock error anomaly processing parameter is added in the positioning observation equation of the pseudorange and the carrier phase of each satellite and each frequency of the PPP-B2b, the satellite with the highest elevation angle in the first epoch is selected as the reference satellite in the subsequent epochs, and the value of the positioning observation equation of the reference satellite is set to 0 to eliminate the rank defect of the positioning observation equation; The GPS / BDS-3 double-system double-frequency non-combination real-time PPP positioning model of the PPP-B2b is represented as: ; ; Wherein, C represents BDS-3; G represents GPS; s represents satellite identifier; r represents user receiver; j represents satellite signal frequency; and represent the pseudorange observations of BDS-3 satellites and GPS satellites minus the calculated values, respectively; and denote the carrier phase observations of BDS-3 satellites and GPS satellites minus the calculated values, respectively; and represent the station-satellite line-of-sight unit vectors of the BDS-3 satellite and the GPS satellite respectively; represents the three-dimensional position of the user receiver r; represents the product of the speed of light and the receiver clock error estimated by the BDS-3 satellite, represents the product of the speed of light and the receiver clock error estimated by the GPS satellite, and It absorbs the pseudo-range hardware delay of BDS-3 satellites and GPS satellites at the user receiver end respectively; and represent the tropospheric projection coefficients of BDS-3 satellite and GPS satellite respectively; It represents the wet delay in the tropospheric zenith direction at the user receiver end; and represent the ionospheric conversion coefficients of BDS-3 satellite and GPS satellite respectively; and denote the ionospheric delay estimates on the slant paths of the first frequency for the BDS-3 satellite and the GPS satellite, respectively. It only absorbs the pseudo-range hardware delay at the user receiver end. It absorbs the pseudorange hardware delay of the user receiver and the uncorrected pseudorange hardware delay of the GPS satellite. and represent BDS-3 satellites and GPS satellites respectively. and The jth frequency of the BDS-3 satellite and the GPS satellite absorbs the pseudorange hardware delay and phase hardware delay of the satellite end, and absorbs the ambiguity estimation of the pseudorange hardware delay and phase hardware delay of the user receiver end; and They represent the clock difference abnormal processing parameters added to the positioning observation equations of BDS-3 satellites and GPS satellites respectively.

[0025] The embodiment of the method for processing abnormal jumps of PPP-B2b satellite clock correction values ​​of the present invention has the following beneficial effects: The clock correction values ​​and broadcast ephemeris of the GPS satellites and BDS-3 satellites of PPP-B2b are collected by the user receiver; the clock correction values ​​of the GPS satellites are used to determine whether the GPS reference satellites of the current epoch and the previous epoch have switched; if the GPS reference satellites of the current epoch and the previous epoch have switched, the reference change is calculated based on the clock correction values ​​of the common-view GPS satellites of the current epoch and the previous epoch, and the clock correction values ​​of all visible GPS satellites of the current epoch are corrected based on the reference change to obtain the corrected clock correction value of the GPS satellite; the corrected clock correction value of the GPS satellite and the clock correction value of the BDS-3 satellite are superimposed on the broadcast ephemeris to calculate The precise satellite clock error parameters are recovered based on the satellite clock error parameters. The precise satellite clock error between the current epoch and the previous epoch is differentially processed to obtain the precise satellite clock error differential value for each satellite. When the precise satellite clock error differential value of the target satellite is greater than a preset threshold, it is determined that there is an abnormal jump in the clock error correction value of the target satellite in the current epoch. The system then determines whether the target satellite is a reference satellite. If not, the clock error abnormality processing parameters in the positioning observation equation of the target satellite are initialized to absorb the abnormal jump in the clock error correction value. If so, the clock error abnormality processing parameters in the positioning observation equation of all satellites in the current epoch are initialized to absorb the abnormal jump in the clock error correction value. To address the random abnormal jump in satellite clock error correction values ​​in PPP-B2b, the system recovers the PPP-B2b precise clock error and introduces the clock error abnormality processing parameters in the positioning equation to detect and process random abnormal clock error jumps in real time. This can avoid jumps in real-time PPP positioning results caused by clock error abnormality and improve the continuity and reliability of PPP-B2b real-time precise positioning results.

[0026] In combination with the PPP-B2b satellite clock error correction value abnormal jump processing method described in the above embodiment, the PPP-B2b satellite clock error correction value abnormal jump processing system is described below through an embodiment.

[0027] like Figure 2 As shown, an embodiment of the present invention provides a PPP-B2b satellite clock correction value abnormal jump processing system, including: The data acquisition module 201 is used to collect clock correction values ​​and broadcast ephemeris of PPP-B2b GPS satellites and BDS-3 satellites through user receivers; The GPS reference satellite switching determination module 202 is used to determine whether the GPS reference satellite of the current epoch and the previous epoch has switched based on the GPS satellite clock correction value; The GPS satellite clock error correction module 203 is configured to calculate a reference change based on the clock error correction values ​​of the common-view GPS satellites in the current epoch and the previous epoch if the GPS reference satellites in the current epoch and the previous epoch are switched, and to correct the clock error correction values ​​of all visible GPS satellites in the current epoch based on the reference change to obtain a corrected clock error correction value of the GPS satellite; The satellite clock error recovery module 204 is used to add the corrected clock error values ​​of the GPS satellite and the clock error correction values ​​of the BDS-3 satellite to the broadcast ephemeris, calculate the satellite clock error parameters, and recover the precise satellite clock error based on the satellite clock error parameters; The abnormal jump detection module 205 is used to perform differential processing on the precise satellite clock error of the current epoch and the previous epoch to obtain the precise satellite clock error difference value of each satellite; when the precise satellite clock error difference value of the target satellite is greater than a preset threshold, it is determined that there is an abnormal jump in the clock error correction value of the target satellite in the current epoch; The abnormal jump processing module 206 is used to determine whether the target satellite is a reference satellite; if not, the clock error abnormal processing parameters in the positioning observation equation of the target satellite are initialized to absorb the abnormal jump part of the clock error correction value; if so, the clock error abnormal processing parameters in the positioning observation equations of all satellites in the current epoch are initialized to absorb the abnormal jump part of the clock error correction value.

[0028] The beneficial effects of the embodiments of the present invention are: In response to the random abnormal jump phenomenon of satellite clock correction values ​​in PPP-B2b, by recovering the PPP-B2b precise clock error and introducing clock error processing parameters in the positioning equation, random abnormal clock error jumps can be detected and processed in real time. This can avoid the jumps of real-time PPP positioning results caused by clock error abnormal values ​​and improve the continuity and reliability of PPP-B2b real-time precise positioning results.

[0029] Those skilled in the art will appreciate that embodiments of the present invention may be provided as methods, systems, or computer program products. Thus, the present invention may take the form of an entirely hardware embodiment, an entirely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, the present invention may take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to magnetic disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0030] The computer program instructions can also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer-implemented process such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the functions specified in the flowchart or flows and / or block diagram block or blocks. Figure 1 one or more flow or flows and / or block diagram block or blocks. Figure 1 one or more flow or flows and / or block diagram block or blocks.

[0031] These computer program instructions can also be stored in a computer readable memory that can direct a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the computer readable memory produce an article of manufacture including instructions which implement the flowchart or flows and / or block diagram block or blocks. Figure 1 one or more flow or flows and / or block diagram block or blocks. Figure 1 one or more flow or flows and / or block diagram block or blocks.

[0032] The computer program instructions can also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer-implemented process such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the functions specified in the flowchart or flows and / or block diagram block or blocks. Figure 1 one or more flow or flows and / or block diagram block or blocks. Figure 1 one or more flow or flows and / or block diagram block or blocks.

[0033] The above merely provides an embodiment of the present application, but is not intended to limit the present application, and any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall fall within the scope of the claims of the present application.

Claims

1. A method for processing abnormal jumps in PPP-B2b satellite clock correction values, characterized in that: include: Collect clock correction values ​​and broadcast ephemeris of PPP-B2b GPS satellites and BDS-3 satellites through user receivers; Determining whether a switch occurs between the GPS reference satellites of the current epoch and the previous epoch based on the clock error correction value of the GPS satellite; If the GPS reference satellites of the current epoch and the previous epoch are switched, a reference change is calculated based on the clock correction values ​​of the common-view GPS satellites of the current epoch and the previous epoch, and the clock correction values ​​of all visible GPS satellites of the current epoch are corrected based on the reference change to obtain a corrected clock correction value of the GPS satellite; Adding the corrected clock error correction value of the GPS satellite and the clock error correction value of the BDS-3 satellite to the broadcast ephemeris, calculating the satellite clock error parameters, and recovering the precise satellite clock error based on the satellite clock error parameters; performing differential processing on the precise satellite clock error between the current epoch and the previous epoch to obtain a precise satellite clock error differential value of each satellite; When the precise satellite clock error difference value of the target satellite is greater than a preset threshold, determining that the clock error correction value of the target satellite in the current epoch has an abnormal jump; Determining whether the target satellite is a reference satellite; If not, initializing the clock error abnormality processing parameters in the positioning observation equation of the target satellite, thereby absorbing the abnormal jump part of the clock error correction value; If so, the clock error abnormality processing parameters in the positioning observation equations of all satellites in the current epoch are initialized to absorb the abnormal jump part of the clock error correction value.

2. The method for processing abnormal jumps of PPP-B2b satellite clock correction values ​​according to claim 1, characterized in that: The types of broadcast ephemeris are divided into GPS LNAV broadcast ephemeris and BDS-3 CNAV1 broadcast ephemeris.

3. The method for processing abnormal jumps of PPP-B2b satellite clock correction values ​​according to claim 2, characterized in that: The determining, based on the clock error correction value of the GPS satellite, whether a switch occurs between the GPS reference satellites of the current epoch and the previous epoch, includes: Obtaining a clock correction value of the GPS satellite at a previous epoch; Comparing the clock error correction value of the GPS satellite at the previous epoch with the clock error correction value of the GPS satellite at the current epoch; If the clock error correction value of only one target GPS satellite in the current epoch is 0, the target GPS satellite is used as the GPS reference satellite, and it is determined whether the GPS reference satellite in the current epoch is consistent with the GPS reference satellite in the previous epoch; if they are inconsistent, it is determined that a GPS reference satellite switch has occurred; if they are consistent, it is determined that no GPS reference satellite switch has occurred; If the clock error correction values ​​of all GPS satellites in the current epoch are not 0, the GPS reference satellite cannot be determined, and it is determined that no GPS reference satellite switching has occurred; If the clock error correction values ​​of the multiple GPS satellites in the current epoch are 0, the GPS reference satellite of the previous epoch is used as the GPS reference satellite of the current epoch, and it is determined that no GPS reference satellite switching occurs.

4. The method for processing abnormal jumps of PPP-B2b satellite clock correction values ​​according to claim 3 is characterized in that: The step of calculating a reference variation based on the clock error correction values ​​of the common-view GPS satellites of the current epoch and the previous epoch, and correcting the clock error correction values ​​of all visible GPS satellites of the current epoch based on the reference variation to obtain a corrected clock error correction value of the GPS satellite comprises: Performing differential processing on the clock error correction values ​​of the common-view GPS satellites of the current epoch and the previous epoch to obtain a differential value of each common-view GPS satellite; Calculating an average of the differential values ​​of all common-view GPS satellites to obtain a reference change between the current epoch and the previous epoch; The reference variation is used to correct the clock error correction values ​​of all visible GPS satellites in the current epoch to obtain the corrected clock error correction values ​​of the GPS satellites.

5. The method for processing abnormal jumps of PPP-B2b satellite clock correction values ​​according to claim 4 is characterized in that: The method of superimposing the corrected clock error correction value of the GPS satellite and the clock error correction value of the BDS-3 satellite onto the broadcast ephemeris to calculate the satellite clock error parameter, and recovering the precise satellite clock error according to the satellite clock error parameter, comprises: The satellite clock error parameters are calculated by adding the corrected clock error values ​​of the GPS satellite and the BDS-3 satellite to the broadcast ephemeris. ; According to the satellite clock error parameters Recover the precise satellite clock error , the calculation formula is: ； Among them, the Represents the speed of light under vacuum conditions; Indicates the preset clock correction value, which is preset according to the PPP-B2b correction product.

6. The method for processing abnormal jumps of PPP-B2b satellite clock correction values ​​according to claim 1, characterized in that: After superimposing the corrected clock error correction value of the GPS satellite and the clock error correction value of the BDS-3 satellite onto the broadcast ephemeris and calculating the satellite clock error parameter, and recovering the precise satellite clock error according to the satellite clock error parameter, the method further comprises: Add a clock error abnormality processing parameter to the positioning observation equations of the pseudorange and carrier phase of each satellite at each frequency of the PPP-B2b, select the satellite with the highest elevation angle in the first epoch as the reference satellite for subsequent epochs, and set the value of the positioning observation equation of the reference satellite to 0 to eliminate the rank deficiency of the positioning observation equation; The GPS / BDS-3 dual-system dual-frequency non-combined real-time PPP positioning model of PPP-B2b is expressed as: ； ； Wherein, C represents BDS-3; G represents GPS; s represents satellite identifier; r represents user receiver; j represents satellite signal frequency; and stated Respectively represent the pseudorange observation values ​​of the BDS-3 satellite and the GPS satellite minus the calculated values; and stated Respectively represent the carrier phase observation values ​​of the BDS-3 satellite and the GPS satellite minus the calculated values; and stated Respectively represent the station-satellite line-of-sight unit vectors of the BDS-3 satellite and the GPS satellite; represents the three-dimensional position of the user receiver r; represents the product of the speed of light and the receiver clock error estimated by the BDS-3 satellite, represents the product of the speed of light and the receiver clock error estimated by the GPS satellite, and stated The pseudo-range hardware delays of the BDS-3 satellite and the GPS satellite at the user receiver are absorbed respectively; and stated Respectively represent the tropospheric projection coefficients of the BDS-3 satellite and the GPS satellite; Indicates the wet delay in the troposphere zenith direction at the user receiver end; and stated Respectively represent the ionospheric conversion coefficients of the BDS-3 satellite and the GPS satellite; and stated Respectively represent the ionospheric delay estimates on the slant paths of the first frequencies of the BDS-3 satellite and the GPS satellite, It only absorbs the pseudorange hardware delay at the user receiver end. It absorbs the pseudo-range hardware delay of the user receiver end and absorbs the uncorrected pseudo-range hardware delay of the GPS satellite end; the and represent the BDS-3 satellite and the GPS satellite respectively; the and stated The j-th frequencies of the BDS-3 satellite and the GPS satellite absorb the pseudorange hardware delay and phase hardware delay of the satellite end, and absorb the ambiguity estimation of the pseudorange hardware delay and phase hardware delay of the user receiver end; and stated They respectively represent the clock difference abnormal processing parameters added to the positioning observation equations of the BDS-3 satellite and the GPS satellite.

7. The method for processing abnormal jumps of PPP-B2b satellite clock correction values ​​according to claim 6, characterized in that: The satellite clock error of PPP-B2b presents a relatively stable feature in each continuous arc, and the clock error abnormality processing parameters are set to a random walk process.

8. A PPP-B2b satellite clock correction value abnormal jump processing system, characterized by: include: Data acquisition module, used to collect clock correction values ​​and broadcast ephemeris of PPP-B2b GPS satellites and BDS-3 satellites through user receivers; A GPS reference satellite switching determination module is used to determine whether the GPS reference satellite of the current epoch and the previous epoch has switched based on the clock error correction value of the GPS satellite; A GPS satellite clock error correction module is configured to calculate a reference variation based on the clock error correction values ​​of the common-view GPS satellites of the current epoch and the previous epoch if the GPS reference satellites of the current epoch and the previous epoch are switched, and to correct the clock error correction values ​​of all visible GPS satellites of the current epoch based on the reference variation to obtain a corrected clock error correction value of the GPS satellite; A satellite clock error recovery module is used to superimpose the corrected clock error value of the GPS satellite and the clock error correction value of the BDS-3 satellite onto the broadcast ephemeris, calculate the satellite clock error parameters, and recover the precise satellite clock error based on the satellite clock error parameters; an abnormal jump detection module, configured to perform differential processing on the precise satellite clock error between the current epoch and the previous epoch to obtain a precise satellite clock error differential value of each satellite; When the precise satellite clock error difference value of the target satellite is greater than a preset threshold, determining that the clock error correction value of the target satellite in the current epoch has an abnormal jump; an abnormal jump processing module, configured to determine whether the target satellite is a reference satellite; if not, to initialize a clock error abnormal processing parameter in the positioning observation equation of the target satellite, thereby absorbing the abnormal jump portion of the clock error correction value; If so, the clock error abnormality processing parameters in the positioning observation equations of all satellites in the current epoch are initialized to absorb the abnormal jump part of the clock error correction value.

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